PHRASE
在听力范围之内/在听力范围之外
If you are within earshot of someone or something, you are close enough to be able to hear them. If you are out of earshot, you are too far away to hear them.
例句
It is within earshot of a main road...
那里能够听见大马路的车水马龙声。
Mark was out of earshot, walking ahead of them.
马克走在前面，听不见他们的声音。